Electric furnace.



No. 657,736. Patented Sept. II, |900.l

W. S. HURRY.

ELECTRIC FURNACE.

(Application fxled Nov. 23, 1897.;

(No Model.) 3 Sheets-Sheet I.

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No. 657,736. Patented Sept. Il, |900. W. S. HURRY.

ELECTRIC FURNACL Application med Nov. 23, 1897.) (No Model.) f A3Sheets-Sheet 2.

No. 657,736. Patented Sept. Il, |900.

W. S. HURRY.

ELECTRIC FURNACE.

(Application tiled Nov. 23, 1897.; (No Model.; 3 Sheets-Sheet 3.

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UNITED STATES PATENT OFFICE.

`/VIILIAM SMITH HORRY, OF SAULT STE. MARIE, MICHIGAN, ASSIGNOR TO THEUNION OARBIDE COMPANY, OF CHICAGO, ILLINOIS.

ELECTRIC FU RNACE.

SPECIFICATION forming part of Letters Patent N o. 657,736, datedSeptember 11, 1900.

AApplication filed November 28, 1897. Serial No. 659,543. (No model.)

To all whom t may concern:

Be it known that I, WILLIAM SMITH HORRY, a subject of Her Majesty theQueen of England, residing at Sault Ste. Marie, Michigan, have inventedcertain new and useful Improvements in Electric Furnaces, of which thefollowing is a specification.

One object of my invention is to cheapen the production of carbid ofcalcium.

Another object of my invention is to produce carbid of calcium of goodand uniform quality; and to these and other ends my invention comprisesthe furnace hereinafter described and claimed.

The nature, characteristic features, and scope of my invention will bemore fully understood from the following descriptiomtaken in connectionwith the accompanying drawings, forming part hereof, and in which Figurel is an elevational view, with parts broken away, of a furnace embodyingfeatures of my invention. Fig. 2 is a view, principally in centralsection, of the same; and Fig. 3 is a sectional view taken on the line 33 of Fig. 2.

Upon a suitable framework or base a is supported a furnace h, which maybe of any cross-section; but from the following` description it willappear that certain advantages are obtained by making it of circularcross-section. Intermediate of the ends of this furnace b areelectrodes, as c and c', so that beneath the electrodes is acarbid-chamber b', and above the electrodes is a kilnchamber h2.Adjacent to the electrodes and in the walls of the furnace may beprovided suitable peep and Stoke holes b3 and h4, as The electrodes cand o' or pencils, as they are sometimes called, are arranged parallelwith the axis of the furnace and with the direction of travel of thematerial through it and in such a way as to clear the side Walls of thefurnace. They are suspended, as shown, by means of chains c2, which aresecured in any convenient manner at or near the open top of the furnaceand which aord some latitude of movement to the electrodes. The currentis conveyed to these electrodes or pencils by way of conductors d andd,led in through and insulated from the walls of the furnace andsupported, if need be, as by the chains c2. Underneath the furnace thereis an elevator, lift, or movable furnace-bottom e, which may be raisedand lowered by suitable mechanism. As shown, this is accomplished bymeans of a threaded shaft c', rotary nut c2, held against endwisemotion, spurwheel c3, connected with said nut, pinion e", and handwheelci, or capstan-head c6. Of course other mechanism may be employed foroperating the lift. At the base of the furnace and at a suitabledistance below the electrodes and above the lowest position of the liftor elevator are provided nipping and supporting devices. The pointedscrews f are such devices and are mounted in a suitable yoke or support,as fl Instead of coke and lime the described furnace will use charcoaland limestone, although coke and lime maybe employed; but I believe thatunder certain conditions a material economy may be effected by the useof charcoal and limestone. The employment of carbonate rather than oxidas raw material involves the expenditure of an unnecessary amount ofcurrent, since an additional heat consuming reaction is therebyintroduced; but this may be advantageous under certain conditions-such,for example, as the presence of inexpensive current and of a convenientsource of carbonate of lime and the absence of facilities for obtainingoxid. By constructing an electrical furnace that is absolutely closed,asdescribed, except at the top, and by burying the arc deeply in thematerial a very efficient furnace is obtained because of theregenerative action of the furnace, the heat in escaping being compelledto traverse the incoming materials, and thus prepare them for themelting process. Such Waste heat traversing limestone fed in at the topburns it, and thereby con verts it into lime. The gases evolved from thetop of the furnace give off most of their heat previous to their escape,and they consist very largelyof carbon dioxid, a non-combustible gas, sothat iiames are not evolved from the furnace to the same extent as inother furnaces. In con sequence of the absence of flames spurting fromthe furnace and of the fact that the arc is deeply buried it followsthat materials are IOO not blown from the furnace, whereby waste isavoided and the absence of dust is insured. Since the electrodes areparallel with the line of gravitation of the material through thefurnace, gases following them do not spurt/out, but are directed towardthe incoming material. The process practiced by means of the describedfurnace may be continuous in the sense that the fusing` action iscontinuous and the delivery is interrupted forsuch comparatively-shortintervals of time as do not destroy the continuity of the fusing action,as will be hereinafter described. Moreover, the furnace is comparativelyinexpensive to i build and takes up relativelya small amount t of space.lt requires very little stoking and when filled up with raw materialwill run for 1 manyhourswithoutrefilling. Obviously this isadvantageous. By making the furnace 5 round in cross-section. orcylindrical the caleium carbid willalso be cylindrical and pieces t ofit can be advantageously operated upon by a machine resemblinga lathefor the removal of outside shell or scale. l The mode of operation ofthe described fun nace may be stated as follows: The lift, elevator, orfurnace-bottom e is brought into elevated position and fine coke is putinto the top of the cylinder in sufficient quantity to i short-circuitthe pencils or electrodes c c/ and i start the arc. Materials which maybe either lime and coke or limestone and charcoal are fed int-o the topof the furnace until the arc I is buried7 for example, some three orfour feet, more or less. As the carbid of calcium i is formed itreducesthe resistance of the furnace, causing the am perage of the circuit torise, which fact may be noted by reference to an ampere-meter. rlheattendant observing this slowly lowers the elevator or fu rnace-bottome,forexample,by means of the hand-wheel e5 and described mechanism.lowering of the elevator or furnace-bottom may be performed in a varietyof ways, ald, though the means described are the best known to me atthis time for accomplishing that purpose; This goes on untilthe furnacelbottom or elevator has reached its lowest position and the carbidprotrudes below the furnace proper. Duringthis operationlimestone, l ifused, is burned in the kiln portion b2 of the l furnace to lime byotherwise waste heat. l The material passes through the furnace underthe intiuence of gravity in a direction parallel with the longer axes ofthe electrodes, thus not unduly injuring them, and the carbid descendsthrough the carbid-chamber b', whose form it takes and is cooled thereinas well as in its passage between the standards CL, that support thewhole apparal tus. When the carbid protrudes for a sufficient distancebelow the furnace, it is broken off by the nipping devices, as shown, bysetting up the pointed screws f. The stick or piece thus broken off isremoved from the elei vator e and is cylindrical, if such was the;During this time thel form of the furnace.

Of course the i' contents of the furnace are held in position by thedescribed supportii'ig devices. In the present inst-ance the screws j"serve to support the solid contents of the carl'iid-chamber b', which inturn support the contents of thc superstructure or kiln, the currentoperating to fuse material which of course is fed in from time to timeand at appropriate intervals from the top of the furnace. After theremoval of the stick of carbid thus cut oi'f the elevator is again runup and the supporting and nipping devices f are returned to theiroriginal positions, so as to clear it and release the contents of thecarbid-chamber li', which then rest on the elevator. The described stepsare repeated as often as necessary and the operation carried onindefinitely.

lt will be obvious to those skilled in the art to which my inventionappertains that modifications may be made in details without departingfrom the spirit thereof. Hence l do not limit myself to the preciseconstruction and arrangement of parts hereinabove set forth andillustrated in the accompanying drawings; but,

Having thus described the nature and objects of my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

l. The combination with an electric furnace constructed for thecontinuous delivery of carbid, of pointed clamp-screws mounted outsideof the furnace and movable inward to nip olf the finished product as itis delivered from the furnace, and a movable furnace-bottom 'constructedand arranged to support the weight of the contents of the furnace and ofthe product from underneath and to carry the product and present itbetween the points of the screws, substantially as described.

2. The combination with an electric furnace constructed for thecontinuous delivery of carbid, of, a movable furnace-bottom constructedand arranged to support the weight of the contents of the furnace and ofthe product from underneath and to carry the product, and devicesconstructed and arranged to cut off the iinished product as it isdelivered from the furnace, substantially as described.

3. An electric furnace comprising the combination of a framework, acarbid-chamber mounted on the framework, a furnace proper mounted on thecarbid-chamber, a kiln-chamber mounted on the furnace proper, electrodeslocated in and having their axes parallel with the axis of the furnaceproper, a movable furnace-bottom, lift or elevator, and clamping devicescooperating with said elevator and furnace, substantially as described.

In testimony whereof I have hereunto signed my name.

WILLIAM SMITH HORRY.

In presence of- C. A. HALL, J. M. MOREHEAD.

IIO

